There is a requirement in industry for the measurement of conditions such as strain or temperature at all points over long distances. Typical uses are for monitoring oil and gas wells, long cables and pipelines. The measurements can be displayed or analysed and used to infer the condition of the structures. Distributed temperature sensors (DTS) often use Raman or Brillouin components of scattered light in optical fibres as the means to determine the temperature. Here, light from an optical source is launched into a fibre and the small amount of light that is scattered back towards the source is analysed. By using pulsed light and measuring the returning signal as a function of time, the backscattered light can be correlated to distance along the fibre. This backscattered light contains a component which is elastically scattered (Rayleigh light) and components that are up- and down-shifted in frequency from the source light (Raman and Brillouin anti-Stokes and Stokes light respectively, also known as inelastic scattered light). The powers of the returning Raman components are temperature dependent and so analysis of these components yields the temperature. The powers and frequency of the returning Brillouin components are strain and temperature dependent and so analysis of both components can yield temperature and strain independently.
Such systems have been known for many years. It is also known from “Simultaneous distributed measurement of strain and temperature from noise-initiated Brillouin scattering in optical fibers” by Parker, T. R.; Farhadiroushan, M.; Feced, R.; Handerek, V. A.; Rogers, A. J.; Quantum Electronics, IEEE Journal of, Volume: 34 Issue: 4, April 1998 Page(s): 645-659 to display temperature vs time or distance. The measurements from such systems can be displayed in a windows display environment in the form of a two dimensional graph of temperature versus distance along the bore.
This can be updated periodically, every minute perhaps, and the display can be zoomed to show variations over a small distance. To see variations over time, a single point along the bore can be selected and a two dimensional view of temperature versus time can be viewed in a separate window.
It is also known from U.S. Pat. No. 6,760,665 to provide a graphical user interface (GUI) for a well logging display program for displaying and editing data records included in well logging data. The GUI includes multiple windows and controls for user interaction. The well logging data includes measurements of logging variables collected at successive depths to define the data records. The multiple windows include a first window for displaying depth versus time measurements, a second window for defining a logging variable, a third window for selecting and displaying a first set of instances of the logging variable, and a fourth window for selecting and displaying a second set of instances of the logging variable. The logging variable can be selected from a pull down menu providing options including neutron porosity (NPHI), natural gamma ray, and temperature measurements. This uses data acquired by a sensor-equipped down hole logging tool and categorized as either “real-time” or “recorded mode data.” The term “real-time” data, as used herein, includes data acquired while the logging tool is in the well and transmitted to the surface and recorded shortly after being acquired. The “recorded mode,” data is acquired and stored in a memory device of the logging tool and subsequently retrieved from the memory when the logging tool is brought to the surface.
It is also known that a spreadsheet program such as Microsoft Excel™ can be loaded with well logging data and graphs of temperature variation with time or distance can be displayed or printed. This has been known for many years and enables a user who is experienced to deduce where changes in conditions can be correlated to known physical features at the same location. However this is time consuming and where the measurements can include important changes over short regions, perhaps a few meters, of a long pipe, perhaps many kilometers long, and new readings are obtained every few minutes, then many such changes may be missed and opportunities to take remedial or pre-emptive action may be missed, with costly results.